I have posted about my troubles on this issue previously, so forgive me if you think you have heard this before.

However, I have since done a lot of checking, research, etc., and now think I understand WHAT is going on. I just can't figure out WHY.

I want to fly from Nairobi to Amsterdam on Jan. 5, 2008, on KLM flight 566 in business class. I need this flight to connect with the rest of my itinerary, which I have reserved with a SkyMiles award from Delta.

Since I was told that free award seats are not available on this flight, I resigned to buy my tickets. However, KLM has not loaded its business class fares yet for this flight. I am very new to the ability to check available fare classes on line (through Seatcounter.com and ExpertFlyer.com, etc.), but I have learned that KLM is currently offering only B Class (Economy) and S Class (Standard) on this flight. No business class seats are offered at all at this time, even though the aircraft is a 747 and of course has a business class cabin. I am 99.999% sure that business class is not sold out, because I have learned enough about checking for available classes to now know that a class that is sold out will at least show up on Seatcounter.com or ExpertFlyer.com as having 0 available seats in the class that is sold out. On KLM, the classes C, CN, D, J and Z are business classes, and I is discount business class. Classes A, AN, F and P are first classes. This particular flight shows nothing for any of those classes, not even zeros, but only S and B (which by the way, show 9 seats in each, meaning that 9 or more are available).

My question is, has anyone with more knowledge or experience seen this before? Why would an airline simply not offer an upper class on an aircraft that has it? And if it is just a delayed offering (i.e., you think it will be offered at some point), has anyone had any experience of when that usually occurs. I am really wondering if I should wait and keep checking, or if what I have seen so far indicates that hope is slim.

Thanks.

Have you tried calling KL in the Netherlands? Post this on the KL forum at Flyertalk if you haven't already.

Which AF CDG-IAH flight are you on, AF36 at 10:15am or AF38 at 3:55pm? Because I was going to suggest looking into the possibility of changing your AMS-CDG segment to LHR-CDG and booking NBO-LHR on BA, but the connections might be too tight if you're on the earlier AF flight.

sevendown...Cant remember the exact routing of your return.Is it NBO AMS ATL DFW?.At any rate, once again I have tapped into my TA's GDS system.I dont know how DL books mileage reservations.When I look at what is available Jan 5 NBO ATL via AMS on KL, it in fact does show flight KL566 available in J class, NBO AMS and connceting to flight KL621 AMS ATL. So, yes there are Business Class seats on that flight.But it just depends on how the booking agent acctually "sells" the flights in a mileage reservation.If they sell it NBO AMS, it comes up "0" J seats, for whatever reason.If they try to sell it NBO ATL, then you would conceivably get the flight you are looking for.I hope this is clear and I hope it helps.

Thanks Patty. I am on the earlier CDG-IAH flight. But I still think I might make the connection. It's an alternative that I may have to consider.

BeachBoi -- You are right. If you ask the system to search NBO-ATL, connecting through AMS, it does show J class available. But if you make the same request for NBO-IAH through AMS, it doesn't show J class. Even stranger, try to check NBO-JFK through AMS. It shows all classes, including J, as completely sold out -- all zeros. Moreover, try the NBO-ATL search again and look further down the search results. When you look at some of the code share flights for KL621 the availability for KL566 completely changes. In otherwords, J class shows available if you are flying the KL birds under KL code the whole way, but if you fly the KL birds with a KL code for 566 and a NW code for 621, then J class isnt even shown.

My return is AMS-CDG-IAH-DFW, flying KL, AF and CO. All award tickets. So unless some award seats have come available through Atlanta or elsewhere, right now I think the only way to get free flights is to follow my current itinerary.

This all just makes less sense than before. Why would the itinerary requested make a difference on the number of seats available on a particular flight. If the seats are open on Flight 566 NBO-AMS when you purchase that flight together on the same ticket with Flight 621 AMS-ATL, why would they not be available when you only want to fly on Flight 566? And then why would the same Flight 566 not have the seats if you wanted to fly to IAH or JFK?

Anybody out there encounter this before or know a way around it?

For business class awards, KL flights book into D.

Thanks Patty -- Do you happen to know what class Delta and Air France book their business class awards into? And if I see that class available, does that necessarily mean an award seat is available?

I'm still learning this.

AF and DL are both O for business. Domestic first class segments on DL are R. You should be able to book an award if you see those classes available. I don't know if EF displays those award classes (I don't have a subscription).

Airlines will sell segments as "married connections". It has to do with inventory management. They may have business class seats available to sell if you are connecting to a specific flight; but you can't book the segments separantely.

I just cut and pasted this info on the married segment concept. Sabre® Married Segments is a revenue-maximization tool that enables airlines to join up to three segments together as single unit to enforce the original conditions of a sale. Based on airline decisions, the SabreSonic™ passenger solution handles the married segments as a single unit, making changes or cancellations dependent on airline approval. Airlines experience greater revenue management control since market-specific inventory is protected from unauthorized, partial cancellations.

Well there you go. Thanks orangetravelcat. Now I understand what is happening. I don't fully understand how it benefits the airline to do that, but inventory management is well beyond me.

Now I just have to figure out how to get around it.

Does anyone know if married segments sometimes get "divorced" before the actual flight, and if so how far in advance? My guess is it just depends on how the flights are selling married, but if anyone has any more info I would appreciate it.

Or if you know another way around this please let me know.